Lead Levels in Well Water, Soil, and General Population in Rural Areas of Southern Jiangsu

Objective  To survey lead contamination in well water, soil, and general population in rural areas of southern Jiangsu, and to identify target prevention areas and related risk factors.

Method  In Changshu, a typical city in southern Jiangsu, we set up five sampling points in the east, south, west, north, and center of the rural areas and one sampling point in the urban areas, respectively. We collected three well water samples and three soil samples in each sampling point. A total of 1 233 residents were selected stratified by age ranges and a gender ratio of 1:1. We used ICP-MS to detect lead levels in the samples of well water, soil, and residents' urine and blood.

Result  The results showed that the lead levels in 18 well water samples were below the limit of lead prescribed in the Drinking Water Health Standards (GB 5749-2006) (0.01 mg/L); the highest average lead level(0.67±0.11) μg/L was found in well water samples collected from the rural north sampling point near a fluorochemical industrial park. In terms of lead levels in the soil samples, the rural south sampling point used to be a galvanizing plant showed the highest(89.25±19.83) mg/kg, followed by the rural north sampling point near a fluorochemical industrial park(81.53±44.54) mg/kg, and the pollution index values were 1.12 and 1.02 respectively, indicating mild pollution. The lead levels in urine and blood samples and the exceeding rates of lead in blood samples of the study participants were highest in those dwelt around the above two mentioned sampling points, showing significant differences with other points (P<0.05). Older age, male, smoking, distance from home to main road <100 m were risk factors for elevated blood lead level of the study participants.

Conclusion  There is mild lead contamination in soil in some rural areas in southern Jiangsu. Pollution level is closely related with residents' internal exposure. We should strengthen the prevention and control of environmental pollution, and residents should develop a healthy lifestyle.